摘要 |
<p>Lengths of ribbed tube (10) having ribs which upstand appreciably from the main body of the tube may be coupled together using novel coupling ends (12, 112 and 14, 114, 214) of the tube. Alternatively, such ribbed tube may be coupled to plain walled tube (100). The lengths of tube are provided with first and second cuffed ends, the first end being a smooth walled cuff having a cuff having only shallow ribs reduced height and the second end being belled to couple with a first end of another tube or with plain walled tube smooth first end and the belled second end may be formed to respective outer and inner diameters for good sealing between them.</p> |